In the related art, JP 2013-184648A (Reference 1) discloses a sunroof apparatus. This sunroof apparatus includes a movable panel which can open or close an opening formed in the roof of a vehicle; guide rails which are respectively provided in both edge portions of the opening in a lateral direction of the vehicle; support brackets, front end portions of which are supported by the guide rails, and which support both edge portions of the movable panel in the lateral direction of the vehicle; and sliding members which are provided so as to be able to move along the guide rails, and are connected to the support brackets. An electric driving source drives the movement of the sliding members. Along with the movement of the sliding members, in a fully closed state of the movable panel, when the support brackets pivotally turn relative to front and portions of the support brackets such that rear ends of the support brackets are raised, the movable panel is tilted upward, and when the front end portions continuously move to the rear of the vehicle, the movable panel slides while being tilted upward.
A substantially U-shaped holding groove is formed in each of the sliding members in such a manner that the holding groove opens toward the rear of the vehicle. A substantially circular column-shaped holding pin is fixedly attached to each of the support brackets in such a manner that the holding pin protrudes toward the inside of the vehicle in the lateral direction of the vehicle. Since the holding pins are engageably inserted into the holding grooves when the movable panel is in a fully closed state, even if a load is applied to the movable panel from a vehicle's passenger compartment (from below the movable panel), for example, when the head of a passenger comes into contact with the movable panel, the support brackets are prevented from being twisted in a certain direction, and both the support brackets are in more stable positions due to the movable panel.
In the sunroof apparatus disclosed in Reference 1, for example, when a large load is applied to the fully closed movable panel from the vehicle's passenger compartment due to a vehicle rolling over, both the support brackets may be twisted in a reverse direction, and may be in unstable positions.